Distributed range & status
These snakes are inhabitants of plains, hills of Sri Lanka up to 1000m, forests & almost every where in the country except for very high hill sides. They are abundant in lightly forested habitats, frequenting trees, hedges, bushes & gardens. They’re also found in India, Nepal, Myanmar, and Thailand & near Peninsular.
Scales
rostral |
small |
frontal |
Elongated touching 8 shields |
supraoculars |
Larger than frontal |
parietals |
The entire system is widest shortly after the point upon contact with the Supraoculars. The end of the Frontal sinks into the middle of the system and the line of contact with both Supraoculars is a near straight line. |
prefrontals |
Taper towards the anterior |
nasals |
1 scale not divided Elongated and situated towards the sides of the head. Nostril can be found towards the posterior of the shield. |
internasals |
The combined system takes the form of spike |
loreals |
absent |
preoculars |
1 big scale is divided into 3 shields of which the topmost touches the Frontal. |
postoculars |
Divided into two shields. |
temporals |
Divided into two shields, of which the lower one is smaller (1-2)+(2-4) |
Supralabials |
8 (4 & 5 connected with eye) |
mental |
Minute and semi-circular |
infralabials |
6 pairs of which the first pair is petal shaped. The next 3 are small and nondescript while the last 2 are the large and prominent of which the last pair is the largest. |
sublinguals |
Divided of which the Anterior pair is petal shaped and the Posterior pair is slender and separated by smaller shields |
coastals |
Vertebral row enlarged. The next six rows are nearly equal in size. The Ultimate row is the largest and the posterior scales are rounded |
ventrals |
168-206 (In rare abnormal specimens the last Ventral may be divided.) |
anal |
divided |
subcaudals |
127-174 |
The shields on the head of this snake have been tailored by evolution to fit into its unique head. It is rare among other snakes to find shields that have been distorted to the proportions of that of this specie. The body has 15 of mid body scale rows.
Characteristics
These snakes contain a very long snout ending with a pointed tip. They have a long, cylindrical prehensile tail. Rostral appendage is seen in grown snakes. Eyes contain horizontal pupils & a concave loreal region giving a vast visible area. Dorsal median groove is present. Clear neck is present. Light, long & slender body is present.
Colour
Dorsal body is light or dark green or olive brown mixed. It’s often a bright green colour but some times even brown. Lips & chin is white in colour. Outer margin of the ventrals contain a longitudinal yellow or white line. Ventral body is white, light green, bright green or rarely brown in colour. Black & white stripes show on the front body when excited.
Venom
They’re mildly venomous. Opisthoglyphous type poison gland is present.
Dentition
These snakes contain of Maxillary: 13 or 14, Palatine: 7 to 10, Pterygoid: 17 to 28 & Mandibular: around 20
Behavior
They are diurnal & live on trees. When disturbed they try to bite & are very sensitive for movements in the environment. It has a very nasty disposition and does not like to be handled. Its habit of darting at its adversary's face is the basis of the myth that it deliberately plucks eyes hence its earning native Singhalese, Tamil and other Indian names. It does not hesitate to strike if provoked but is very easy to handle once its head and eyes are covered up in rags rendering its jaws ineffective. Strongly dislikes captivity and often strikes the glass walls of the vivarium often injuring and disfiguring itself in the process. Unlike many other snakes the Green Vine Snake lets go once bitten often leaving teeth gouged in its enemy's flesh. The bites are made by rear fang which causes mild pain, itchiness & swelling.
Breeding
They mate in June & produce offspring 3-23 by ovoviviparous. Young ones are born between March & December, after 172 days. Young are frequently born still surrounded by a membrane. Its gestation period is assumed to be around 6 months. The brood varies from 3 to 15 with extreme cases which reach well into the 20's.
Growth
At birth they measure 200-350mm & grow up to 1000-1500mm. Females are larger than the males and the males have proportionately longer tails.
Food
They hide in ambush to catch the prey for small mammals, birds, geckoes & lizards. Fish, tadpoles, & other small snakes are also known to be including in the diet. Its superb camouflage enables it to stalk its prey with ease. (Its camouflage is so effective that it is often passed off as a 'green twig' by many herpetologists) Once the prey is in striking distance it coils itself and darts towards its prey with lightning speed. The prey is often seized by the neck and killed by suffocation caused by crushing its victim’s throat with its jaws. Its venom plays a minor role in its hunting but does appear to assist in the killing process. This snake waits until its prey is completely dead before swallowing it and is reputed to tenaciously hold on to struggling prey often for more than an hour before its prey gives up the game. Rarely does its prey escape. It also includes small snakes in its diet. Big sized prey is swallowed by the help of mandibles.
Identification
The characteristic form of this snake often divulges its identity at a distance. However in order to distinguish it from its close relative A.pulverulentus it should be noted that in Sri Lanka A.nasuta is more pale to dark green with white stripes while A.pulverulentus is more towareds brownish grey. The latter often has more Ventral and Subcaudal scales, along with numerous smaller scales on its nasal appendage.
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